Differential expression of two closely related deoxyribonuclease genes, nucA and nucB, in Bacillus subtilis

Authors

  • Douwe van Sinderen,

    1. Groningen Biomolecular Sciences and Biotechnology Institute. Department of Genetics, University of Groningen, Kerklaan 30, NL-9751 NN Haren The Netherlands.
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  • Rense Kiewiet,

    1. Groningen Biomolecular Sciences and Biotechnology Institute. Department of Genetics, University of Groningen, Kerklaan 30, NL-9751 NN Haren The Netherlands.
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  • Gerard Venema

    Corresponding author
    1. Groningen Biomolecular Sciences and Biotechnology Institute. Department of Genetics, University of Groningen, Kerklaan 30, NL-9751 NN Haren The Netherlands.
    • *For correspondence. Tel. (50) 632093; Fax (50) 632348.

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Summary

Despite the lack of involvement of the competence-specific, membrane-associated deoxyribonuclease (DNase) in competence development, the expression of the gene encoding this protein, nucA, was shown to be dependent on the competence signal transduction pathway, and in particular on ComK, the competence transcription factor, which was shown to bind to the DNA region upstream of nucA. The expression of nucB, specifying an extracellular DNase, which was cloned on the basis of its homology to nucA, was shown to be sporulation-specific and dependent on the gene products of spo0A and spollG, the latter constituting an operon responsible for the synthesis of the mother-cell-specific sigma factor σE. The observed differential expression of nucA and nucB demarcates the appearance of DNase activities which are either associated with the cytoplasmic membrane or secreted into the medium during different post-exponential growth-phase processes.

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